No abstract available.
beta-Lactamases*

No abstract available.
beta-Lactamases*

Background:blaTEM, bla SHV, blaCTX \ufffd?M, blaOXA genes encode for extended spectrum \u03b2 \ufffd?lactamases resistance to broad \ufffd?spectrumcephalosporins. Many species belonging the family Enterobacteriaceae possess these genes. Objectives: To determine the distribution of blaTEM, bla SHV, blaCTX \ufffd?M and blaOXA genes in enteroaggregation E.coli (EAEC) strains. Subjects and method: 67 EAEC strains causing diarrhea and 18 strains isolated from healthy children were screened by PCR with primers specific to blaTEM, bla SHV, blaCTX \ufffd?M \ufffd?1and blaOXA genes. Results: The prevalence of ESBL genes in diarrheagenic EAEC strains and those isolated from healthy children were 83.6 and 72.2 %, respectively. The highest prevalence blaTEM gene (82% in diarrheagenic EAEC strains and 72.2% in isolated from healthy children) was followed by that of blaOXA gene (11.9 and 11.1% in two EAEC groups). Only 2 strains possess blaSHV gene. The blaCTX \ufffd?M \ufffd?1 was not detected in any EAEC strain. Conclusion: our findings have not only provided additional understanding of the distribution of blaTEM, bla SHV, blaCTX \ufffd?M - 1 and blaOXA genes in EAEC strains but also have a given significance in selecting antibiotics for treatment.
beta-Lactamases/ genetics ; Escherichia coli ;

Background:Resistance to antibiotics due to extended \ufffd?spectrum \ufffd?Lactamase (ESBL) which increased quickly, made treatment much more difficult. However, this matter was not enough to be concerned in our country. Objectives: To investigate the prevalence of ESBL producing among clinical isolates of E.coli, K.pneumoniae and Enterobacter spp and the classification of ESBLs gene by PCR. Subjects and method: 663 strains, including 248 E.coli, 393 K.pneumoniae, 22 Enterobacter spp, isolated from patients in Viet Tiep hospital (Hai Phong), Bach Mai and Pediatric hospital (Ha Noi). ESBLs were detected using modified double \ufffd?disc method. The classification of ESBLs producing strains was implemented by PCR. Results:the percentage of ESBL producing in E.coli, K.pneumoniae and Enterobacter spp is 20.2; 18.3 and 36.4%, respectively. The ESBLs producing strains were co \ufffd?resistant to most of the tested antibiotics. These strains were prevalent in intensive care units (sputum or respiratory fluid samples). TEM, SHV, CTX \ufffd?M, OXA were 87.7; 62.3; 24.6 and 12.3%, respectively. They were detected alone or in combination in the same strain. Conclusion: The rate of ESBLs producing strains is high. ESBLs were marker for multi \ufffd?drug resistance. TEM and SHV type ESBLs are most prevalent in the tested strains.
beta-Lactamases ; Klebsiella pneumoniae ; Enterobacter ; Escherichia coli ;

Extended-spectrum beta-lactamases (ESBLs), mediated by plasmids, can hydrolyze and cause resistance to penicillins, broad spectrum-cephalosporins, and monobactams. Most ESBLs are derived from the widespread broad-spectrum beta-lactamases TEM-1 and SHV-1. There are also other families of ESBLs, including CTX-M and OXA-type enzymes as well as novel unrelated beta-lactamases. This article reviews recent advances in the classification, characteristics, and other molecular biological aspects of ESBLs.
Molecular Biology ; beta-Lactamases ; classification ; genetics

Aims: The detection of the metallo-beta-lactamase (MBL) producing Pseudomonas aeruginosa isolates is crucial for infection control and public health. The present study aimed to investigate the MBL production in carbapenem-resistant P. aeruginosa isolated from various clinical samples in Kastamonu Training and Research Hospital, Turkey. Methodology and results: Seventy-three carbapenem-resistant P. aeruginosa isolates were recovered from different patients between April 2018 and November 2020. Identification of the isolates was performed by conventional methods (culture examination, determination of Gram reaction, and oxidase test) and an automated system (Vitek 2). Antibiotic susceptibility patterns were determined using the Vitek 2 and the results were interpreted based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards. The MBL production was phenotypically investigated using the imipenem-EDTA combined disk test. The presence of beta-lactamase IMP (blaIMP), beta-lactamase VIM (blaVIM) and beta-lactamase GIM (blaGIM) genes were determined using PCR to confirm the MBL production. Seventy-one isolates (97%, n=71/73) were resistant to imipenem, sixty-four isolates (88%, n=64/73) to meropenem and sixty-two isolates (85%, n=62/73) to both imipenem and meropenem. Sixty-five isolates (89%, n=65/73) were defined as multidrug-resistant. The MBL production was detected in 57 isolates (78%, n=57/73) phenotypically. However, the blaIMP, blaVIM and blaGIM genes were not detected in all the isolates. Conclusion, significance and impact of study It was determined that there were no imipenemase (IMP), Verona integron-encoded metallo-beta-lactamase (VIM) and German imipenemase (GIM) type MBLs in carbapenem-resistant P. aeruginosa isolated from Kastamonu Training and Research Hospital. MBL production in carbapenem-resistant P. aeruginosa strains can be investigated phenotypically. However, confirmation of results with molecular tests is especially significant for epidemiological studies.
beta-Lactamases ; Carbapenem-Resistant Enterobacteriaceae ; Pseudomonas aeruginosa

The dogma that ampC genes are located exclusively on the chromosome was dominant until about 10 years ago. Since 1989 over 15 different plasmid-encoded AmpC beta-lactamases have been reported from several countries. Most of these enzymes evolved in two clusters. The major cluster includes several enzymes with a high similarity to CMY-2, which is the closest related chromosomal AmpC enzyme of Citrobacter freundii. A second cluster centers around CMY-1. It is less homogeneous and not closely related chromosomal AmpC enzymes. Molecular diversification by amino acid substitutions does not usually translate into a change in the resistance phenotype. At this time, CMY-2 appears to be the most prevalent and widely distributed. Further global increase of prevalence and diversity of plasmidic AmpC beta-lactamases have to be anticipated in the next millenium.
Microbiology/trends ; Plasmids/genetics* ; Structure-Activity Relationship ; Tissue Distribution ; beta-Lactamases/metabolism ; beta-Lactamases/genetics*

BACKGROUND: A high proportion of currently isolated gram-negative bacilli are resistant to beta-lactams by producing beta-lactamases. beta-lactam and beta-lactamase inhibitor combinations have been successfully used to overcome the resistance. In this study, in vitro antimicrobial activity of a new combination, cefatrizine-clavulanic acid, was determined against gram-negative bacilli isolated from community-acquired urinary track infections. METHODS: Nonduplicate strains of Enterobacteriaceae, isolated in 2003 from urine specimens of outpatients and inpatients of less than 3 hospital days at Severance Hospital, were tested by the NCCLS agar dilution method. RESULTS: Of a total of 204 isolates, 144 (71%) were Escherichia coli and 30 (15%) were Klebsiella spp. MIC50 and MIC90 of cefatrizine for E. coli were 2 microgram/mL and 16 microgram/mL, respectively. MIC90s of both cefaclor and cefoxitin were also 16 g/mL. MIC50 and MIC90 of cefatrizine-clavulanic acid for E. coli were 1 microgram/mL and 4 microgram/mL, respectively, which were 1/2-1/4 of those of cefaclor and cefoxitin. For Klebsiella spp., MIC90 of cefatrizine was 4 microgram/mL with an MIC range of 1->128 microgram/mL, whereas that of cefatrizine-clavulanic acid was 2 microgram/mL with an MIC range of 0.5-32 microgram/mL. In vitro activity of cefatrizine-clavulanic acid was higher than that of cefatrizine. CONCLUSIONS: Improved in vitro activity of cefatrizine-clavulanic acid against isolates of E. coli and Klebsiella spp. from community-acquired urinary track infection suggested that the combination is useful for an empirical treatment of the infection.
Agar ; beta-Lactamases ; beta-Lactams ; Cefaclor ; Cefatrizine ; Cefoxitin ; Enterobacteriaceae ; Escherichia coli ; Humans ; Inpatients ; Klebsiella ; Outpatients

PURPOSE: To evaluate the clinical outcomes of ertapenem administered as an outpatient parenteral antibiotic therapy for intractable cystitis caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. MATERIALS AND METHODS: We retrospectively reviewed a case series of 3 years of therapeutic experience with ertapenem for intractable recurrent cystitis caused by ESBL-producing E. coli. Ertapenem 1 g/d was parenterally administered to the patients on an outpatient basis until the acquisition of symptomatic improvement and negative conversion of urine culture. Demographic and clinical characteristics of patients, antimicrobial resistance, and clinical response data were analyzed from the patients' medical records. RESULTS: During the course of this study, a total of 383 patients were diagnosed with cystitis, and 24 of them showed ESBL-producing E. coli (6.26%). The mean treatment duration of all patients was 8.5 days. The early clinical and microbiological cure rates 0 to 7 days after the end of treatment were 91.7% (22/24) and 90.9% (20/22), respectively. The late clinical and microbiological cure rates 4 to 6 weeks after the end of treatment were 72.2% (13/18) at both time points. CONCLUSIONS: Parenteral ertapenem treatment can be an effective and well-tolerated treatment option for intractable recurrent cystitis by multidrug-resistant ESBL-producing E. coli.
beta-Lactamases ; beta-Lactams ; Cystitis* ; Escherichia coli* ; Escherichia* ; Female* ; Humans ; Medical Records ; Outpatients* ; Retrospective Studies

Humans ; Microbial Sensitivity Tests ; Pneumoconiosis ; microbiology ; Sputum ; microbiology ; beta-Lactam Resistance ; beta-Lactamases ; analysis